49 



specimens. All six species are represented in the "Siboga" collection. From the Atlantic I have 

 only two species, L. typus M.-Edw., and L. Faxonii Borrad. ; L. typus is extremely common 

 in the Atlantic and scarce in the area explored by the "Siboga". 



The genus was established in 1829 by J. Vaughan Thompson, who figured an Atlantic 

 specimen, but did not name the species; in 1837 H. Milne-Edwards named it L. typ7is, but 

 had not seen any specimen. According to Thompson's figure it is a species with long eye- 

 stalks, and as only one form with long-stalked eyes has been found in the Atlantic, where it 

 is extremely common, the name L. fyp^is must be kept for this species. In 1837 Milne-Edwards 

 also established a species from the Indian Ocean, L. Reynaudii\ his figure does not allow a 

 determination, and it is interesting to observe that Dana (1852) described and figured a species 

 with short eye-stalks, and Spence Bate (1888) a species with long eye-stalks under the name 

 L Reynaudii. Judging from Milne-Edwards' figure I think he examined a species with long 

 eye-stalks, but as two species with such eye-stalks exist in the Indian Ocean it will forever be 

 impossible to produce a valid interpretation, and the name L. Reynaudii ought to be dropped. — 

 In 1852 Dana described and figured 4 species, viz. a form with short eye-stalks determined 

 as L. Reynatidii and three new species. Though Kemp (191 3) says: "Dana's treatment is 

 fortunately very good and surpasses that of nearly all subsequent writers", I must unfortunately 

 maintain that it is poor. What Dana described and figured as L. Reynatidii is one of the forms 

 with short eye-stalks, but it is impossible to recognize it. Kemp believes that a feature seen by 

 Dana, viz. the presence of a pair of spinules on sixth abdominal segment of the male, is a 

 valid specific character, but it is no character ; these spinules are those always present in the 

 females and generally lost in the males, but I have found them in single specimens of L. Faxonii 

 and L. Hanscni Nobili. Dana's new species L. acestra is decidedly one of the two species with 

 long eye-stalks, it is a male, and if the figure exhibiting the telson is not very incorrect the 

 specimen drawn was not quite full-grown and, judging from the place of the protuberance on 

 the lower side of telson and especially from the shape of the posterior ventral process on sixth 

 abdominal segment, the specimen in question belonged to L. typus M.-Edw. Of the two other 

 species established by Dana as new L. pacificus is completely unrecognizable, while L. aciciilaris 

 is a quite young, not even half-grown specimen still showing two larval characters, viz. the 

 very short "neck" and the telson nearly as long as the uropods. — In 1905 Nobili established 

 and in 1906 he described more elaborately and figured a new species with short eye-stalks, 

 L. Ha?iseni, which can be recognized with certainty, as he pointed out in the text and showed 

 in the figures two characters, in which this species differs from all others known to me ; his 

 animals were taken in the Bay of Djibouti (the Red -Sea).. 



So many species had been established in 19 14. Several other authors, viz. Eydoux & 

 SouLEYET, Claus, Dohrn, Semper, F.\xon, Boas, Ortmann, Brooks and Kemp, had mentioned 

 or even published figures of Lucifer, referring their specimens with or without a query to L. 

 typus or L. Reynaudii, or distinguishing the form only as Lucifer sp. or Lucifer sp. n.? Some 

 few of these publications, especially those worked out by Claus and Brooks, give important 

 contributions to our knowledge of the type, but for discrimination between forms they are of 

 slight or no significance. — In 1915 L. A. Borradaile published a treatise: "On the Species 



SIBOGA-EXPEDITIE XXXVIII. 7 



